The Not Presto cutterhead

[Fela Borbone]

Hello folks,
This is my new little daugther, a Not Presto cutter head!.Sorry about the pics, my camera is not very good at short distances...
It can be denied that is inspired in the presto 1x heads.It was not my aim to build an exact reproduction of the original but to make my version of this classic.
The magtnets are neodymium linked to de polepieces by two iron bars.
Its damped with just rubber,one of the things I have to change in future versions.
I dont like screw clamps for the stylus, so I implemented a "twist and lock" that is working well,and holds the needle near the edge of the armature , instead of the tail of the stylus.It uses a Presto long or short shank.As can be seen in the photo the armature extends a few milimeters "embracing" the stylus alittle longer to reduce resonant freq in the long shanks.
Other big difference with the original is the suspension.Instead of the clever set up of the original, my blaspheme version has a sort of "hard hinge" carved in its link to the chassis, wich both centers and gives the restoring force.Sadly is not adjustable...
It sounds not bad for a first attempt without any corrective EQ(only IRIAA).It has resonance around 8khz.Ruler flat to 12k is within the reach of a graphic EQ.Peak at resonance is around 4dB only.
Icant compare with my 1C because is Thrashed (and thats the reason I build another one!)but the ligth pattern of the Not Presto is not like the one shown in the Presto brochure...Note that mine was cutted at much higher level,and in 1/3 octave steeps,from 1 khz. no IRIAA.Presto "unretouched photo" seems been taken from rigth above, not at 45 degrees, where the ligth came from.I think I"ll open thread to comment this...Im confused.
I have to change my damping to achieve flatter response.In the other hand,it sounds pretty loud.
Thanks for reading!

[Fela Borbone]

More pics

[Fela Borbone]

Pics

[Soulbear]

Hi Fela,
Kudos to you for making a Mono Cutterhead, Well Done, Bravo!! Soulbear

[Fela Borbone]

...And this is an audio sample.Myshank blank and stylus.No EQ, just IRIAA.The sound is loud.Guitar faded after converting to mono, sorry!
Thanks for reading!

[Fela Borbone]

Thanks Soulbear!

[EpicenterBryan]

Nice Job on the new project Fela!
Cool idea about the twist lock stylus holder. How the heck did you do that? Is there a little spring in there of something? And what did you use for a front cover?

[inspector77]

Great work Fella!

[Fela Borbone]

Thanks Bryan !
Im following the rocking bridge project, kudos!

Yes stylus is held by means of a sort of spring. Its the blade of tiny hand saw. Its heated red hot, then folded. Heated again and not quenched immediatly but after some seconds or it will turn too brittle...the rigth point is found by experiment .different alloys can work differently. The drawings will explain better than me. The other drawing is other version that holds the stylus firmly at all its length... But i need the other end of the hole open to machine properly...

[Fela Borbone]

Alternative twist lock:

[Fela Borbone]

The cover is made out of fibberglass the same used to repair car bodies. I made a mould in plaster from the otiginal but added little pyramids instead of strips, as I dont want it to look exactly like the original, but alike.

[Fela Borbone]

Thanks, inspector!

[EpicenterBryan]

Its heated red hot, then folded. Heated again and not quenched immediatly but after some seconds or it will turn too brittle...the rigth point is found by experiment .different alloys can work differently.

Your ingenuity never ceases to amaze me. Great work there!